Understanding how to approach exam questions helps to boost exam performance. Question types will include multiple choice, structured, mathematical and practical questions.

Don't forget to take a ruler and calculator into the exam.

Maths questions often start with command words like **'Calculate...'** **'Determine...'**, **'Estimate...'** and **'Measure...'**. They will then include blank space for you to show your working.

When an answer to a maths question is marked:

- full marks are given for the right answer (but it is very important to show your working, so you can check your answer and so that, if you make a small slip, you can still get marks for your working)
- marks may be given for working, including substitution and rearrangement
- 'errors carried forward' are worked through to give credit for later working

Errors are carried forward if a later working depends on an earlier answer. You could still get marks if your working is correct but you use the incorrect earlier answer.

If your answer has many decimal places or figures, make sure you give it to an appropriate number of decimal places or significant figures. You may be asked to give units. This may earn you an additional mark, so don’t forget to check whether you need to do this.

Maths questions might ask you to plot or complete a **graph** or **table**. When you draw a graph, make sure you:

- plot each point accurately
- draw a best fit straight line or curve, where appropriate

You may be given a grid with axes labelled and scales already given. Sometimes you may be given an empty grid for you to supply your own axes. When you do this:

- put the independent variable on the x-axis and the dependent variable on the y-axis
- choose even scales and make sure that the points cover at least half the given grid
- label the axes with their quantity and unit, eg time (s)

*Edexcel questions courtesy of Pearson Education Ltd.*

- Question
The table shows information about some of the elements in group 7 of the periodic table.

Element Melting point Boiling point Fluorine -220°C -118°C Chlorine -101°C -35°C Bromine 7°C 59°C Iodine 114°C 184°C Astatine is below iodine in group 7 of the periodic table.

Estimate the boiling point of astatine.

**[1 mark]**Any temperature greater than 184°C. [1]

- Question
The table shows some of the gases in group 0 and some of their properties.

The gases are shown in the order in which they appear in group 0.

Complete the table.

**[3 marks]**Gas Symbol Density Reaction with metals Helium He 0.12 g/dm ^{3}No reaction Neon Ne 1.44 g/dm ^{3}No reaction Argon Ar No reaction Krypton 3.00 g/dm ^{3}No reaction Xenon Xe 3.56 g/dm ^{3}- Kr [1] -
**not**KR, kr or kR - value in the range 1.45 to 2.99 g/dm
^{3}[1] - no reaction [1]

- Kr [1] -

- Question
Some metals react with halogens.

Iron reacts with bromine, Br

_{2}, to form iron(III) bromide, FeBr_{3}.Write the balanced equation for this reaction.

**[2 marks]**- 2Fe + 3Br
_{2}→ 2FeBr_{3} - correct formulae [1]
- correct formulae balanced correctly [1]

- 2Fe + 3Br

- Question
Write the balanced equation for the reaction of sodium with water.

**[3 marks]**- 2Na + 2H
_{2}O → 2NaOH + H_{2} - formulae on left-hand side correct [1]
- formulae on right-hand side correct [1]
- correct formulae balanced correctly [1]

- 2Na + 2H